The present invention is directed to a process for machining a single or multiple groove worm or threaded-type workpiece with a single or multiple groove worm or threaded-type tool and the apparatus for carrying out this process.
German Pat. No. 748.587 discloses a process for contouring by worm-formed grinding tools. A worm-formed gear hob is used as the dressing tool which is brought into operation with the threads of the workpiece. Choice of appropriate contour enables the axle of the dressing tool to be brought parallel to the axle of the workpiece so that for carrying out a dressing operation, the dressing tool which is disposed in combing relation with the workpiece only needs to be moved in a radial direction. The dressing tool has cutting surfaces made of hard metal or other material of extreme hardness. Since the dressing tool stays engaged along with the workpiece throughout the entire contour, the cutting forces during the dressing and, accordingly, the resultant heat are both very high. This leads to finishing difficulties. As a consequence of heat expansion, it is also difficult to stay within tolerances. Further, no flank-forming corrections can be made on the workpiece with this dressing tool.